Question: What are thegroup or class of chemical substances which start with the letter vitamin
Paraphrase: What are thegroup or course of chemical substances which begin with the letter vitamin
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q17339814 . ?sbj rdfs:label ?sbj_label . FILTER(CONTAINS(lcase(?sbj_label), 'vitamin')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: vitamin E, vitamin E, vitamin B6, vitamin B6, vitamin B, vitamin B, vitamin K, vitamin K, vitamin A, vitamin A, vitamin B1 analogue, vitamin B1 analogue